ANN ARBOR, Mich. – Because of heavy graduation losses, there are position battles all over the field for the 2017 edition of the Michigan Wolverines. Both sides of the ball will see stiff competition as Jim Harbaugh’s two massive recruiting classes battle it out on the field for playing time during spring practice, which begins Friday.

While Michigan lost a ton, coaches also believe they have some key pieces returning to go along with a talented, athletic group of recruits.

The three biggest position battles

1. Offensive line: It’s hard to pick just one position on the offensive line, as both tackles and a guard are gone. Center Mason Cole returns, but he may have to move back to left tackle if Michigan can’t find a tackle among its young recruits. Touted true freshman center Cesar Ruiz enrolled early, and Cole’s position could depend on Ruiz’s acclimation. Ben Bredeson returns at left guard (he also could play tackle, if the need arises), and talented sophomore Michael Onwenu should develop into a good player at right guard. The tackle spots are a little more tenuous. Grant Newsome began last season as the starter at left tackle, but is attempting a comeback from a major knee injury that ended his 2016 season early. This is an important spring for senior Juwann Bushell-Beatty, who could emerge from spring as the starting left tackle. The right side is a more difficult call. If coaches are comfortable with Patrick Kugler at guard, Bredeson could play right tackle. Or Bushell-Beaty could end up on the right side, especially if Cole moves to tackle.

2. Wide receiver: There is a lot of young talent, which is a good thing because Michigan was hit hard at this position by graduation. Amara Darboh and Jehu Chesson (and tight end Jake Butt, for that matter) are gone. Grant Perry is the leading returning receiver with 13 receptions, but he is suspended. Highly touted true freshman Donovan Peoples-Jones enrolled early and he already is being tabbed as the next great wide receiver at Michigan. Sophomores Kekoa Crawford and Eddie McDoom will look to become, at the least, important parts of the rotation. There’s also senior Moe Ways. Michigan signed a strong group of receivers, so the holdovers need strong springs or risk being bypassed in the fall.

3. Secondary: Michigan lost three corners and two safeties, so every starting spot is open in the defensive backfield. Sophomore cornerbacks Lavert Hill and David Long played last season as freshmen, and Hill, in particular, would seem to have a high ceiling. Juniors Brandon Watson and Keith Washington and early enrollees Ambry Thomas and Benjamin St-Juste will be looking to impress. Junior Tyree Kinnel seems likely to start at one safety spot, and there are high hopes for sophomore Khaleke Hudson. There’s also Josh Metellus, Jaylen Kelly-Powell and Jordan Glasgow.

The three strongest positions

1. Quarterback: This is a deep position group with a good amount of experience and even more talent. Wilton Speight was solid in his debut season under center and should continue as the starter as a junior, but he will be pushed by talented redshirt freshman Brandon Peters. Peters is Harbaugh’s first-ever quarterback recruit at Michigan and Harbaugh is high on Peters, a former four-star recruit. Speight should lock down the position early as he played well in Harbaugh’s offense last season and seemed to improve weekly.

2. Running back: This group is deep and talented. While there doesn’t appear to be a feature back yet, there are plenty of options. Sophomore Chris Evans produced solid numbers in 2016 and returns as Michigan’s top threat. Senior Ty Issacs and Karan Higdon join him to round out a solid group. The X-factor for Michigan is 2016’s top running back recruit, Kareem Walker, who redshirted as a freshman. If Walker is as good as advertised, he will factor into the running game.

3. Defensive line: While Michigan took heavy losses to graduation on the defensive line, the Wolverines return a lot of talent up front. The starting line looks good. Rashan Gary and Chase Winovich return, and if everything breaks right, they will be the starting ends. Maurice Hurst and Bryan Mone would start at tackle. Sophomore Michael Dwumfour provides depth. But two or three other linemen need to prove they can handle reserve roles. Five-star tackle Aubrey Solomon arrives over the summer.